Process for producing energy in a gas generator system

ABSTRACT

In a gas generator system, a process for producing hot gaseous power by heating bis-(fluoroformyl)-peroxide to give carbon dioxide, carbonyl fluoride, and oxygen.

nited States Patent [191 Pilipovich Jan. 8, 1974 PROCESS FOR PRODUCINGENERGY IN A [56] References Cited GAS GENERATOR SYSTEM UNITED STATESPATENTS [75] Inventor: Donald Pilipoyich, Ventura, Calif. 3,442,9275/1969 Thompson et a1. 149/109 X [73] Asslgnee: gf fig 5 232? onalCarpal-anon Primary Examiner-Benjamin R. Padgett I g AttorneyWil1iam R.Lane, Thomas S. MacDonald [22] Filed: Sept. 26, 1968 and Paul L.Sabatine 21 App]. No.: 762,938

[57] ABSTRACT In a gas generator system, a process for producing hot F60/218 60/ 25 3 93: gaseous power by heating bis-(fiuoroformyl)-per0xide58] Fieid 149/109 to give carbon dioxide, carbonyl fluoride, and oxygen.

4 Claims, 2 Drawing Figures POWER SOURCE PATENTEDJAN 81974 3,783,617,

INVENTOR. DONALD PlLlPOV/CH ATTORNEY 1 PROCESS FOR PRODUCING ENERGY IN AGAS GENERATOR SYSTEM BACKGROUND OF THE INVENTION This invention relatesto a monopropellant gas generator. More specifically, the inventionrelates to the use of a chemical compound, bis-(fluoroformyl)-peroxideas a monopropellant gas generator.

The use of monopropellants as gas generators is well described in theprior art. Monopropellants are con-- ventionally used in small rocketengines, for the attitude control of a space vehicle or in gasgenerators for rocket turbopump drives. The turbopump feed system in arocket system is routinely driven by turbines that derive their powerfrom the expansion of hot monopropellant gases. These latter gases areproduced in a gas generator in the required quantities by means ofchemical reaction of propellants similar to those in thrust chambers.

A monopropellant system must be chemically and thermally stable toinsure good liquid storage properties, yet at the same time it must beeasily decomposed and reactive to permit good combustion properties. Theliquid type prior art monopropellants, hydrazine and hydrogen peroxide,are generally acceptable for certain, limited applications, butdifficulties are often encountered in employing said monopropellants.For example, in a pressurizing tankage or expulsion system containingoxidizers the hydrazine cannot be used. Indeed, all presently knownmonopropellant gas generators are believed to present a hazardoussituation when used to pressurize oxidizer propellanttankage.

The hazardous situation usually arises because of the incompatibility ofthe gas, formed from the monopropellant, and the oxidizer. For thepurpose of illustration, the use of the monopropellant hydrazine N H asa pressurizing agent with the propellant oxidizer CIF is discussedimmediately below. The hydrazine, N H decomposes according to thefollowing equation: N H N +2H While N is inert, the H decompositionproduct is also an excellent reducing agent and it will react vigorouslywith the oxidizerClF according to the general equation CIF +2H 3;HF+HC1.Thus, the gases produced by the decomposition of the hydrazine arevigorously reactive with the oxidizer chlorine trifluoride and creates ahazardous condition. By producing unwanted hydrogen fluoride andhydrogen chloride in its application, condensable gases are-formed whichdetract from the efficiency of operation.

The use of hydrogen peroxide as a monopropellant also producesundesirable conditions. For example, hydrogen peroxide decomposes toproduce water and oxygen. The newly formed water reacts with oxidizerslike chlorine trifluoride and chlorine pentafluoride to produce chlorinedioxide, a very sensitive and explosive material. The reactions betweenthe monopropellant hydrogen peroxide and the oxidizer chlorinetrifluoride can be represented by the following: 2;H O 2H O+O and, 3HO+2ClF -.z' 2ClO +6HF+O Thus, it will be readily appreciated by thoseversed in the subject art that a monopropellant gas must be chemicallyand thermally stable to insure good liquid storage properties and at thesame time it must easily combust to permit good combustion and ignitionproperties. Because these requirements are essentially incompatible withmost chemicals, there are relatively SUMMARY OF THE INVENTION Thisinvention is concerned with the use of a monopropellant gas generator,bis-(fluoroformyl)-peroxide, C F O The compound decomposes on theapplication of heat to give COF CO and O The invention will furtherbecome better understood by reference to the following detaileddescription of the accompanying drawing and disclosure. It is to beunderstood that the annexed sheet of drawing and disclosure is presentedfor the purpose of illustration of presently preferred embodiments ofthe present invention and that the scope and spirit of the invention isnot to be limited thereto.

DESCRIPTION OF THE DRAWING In accompanying drawing, FIG. I, is shown asche matic view of an environment employing the inventive processdisclosed herein, as a source of power in a turbopump system.

In accompanying drawing, FIG. 2, is set forth a schematic view ofanother novel embodiment of the invention in a generalized pressure fedsystem.

DESCRIPTION OF THE INVENTION In attaining the object and features of thepresent invention, it has now been unexpectedly found that bis-(fluoroformyl)-peroxide, C F O can be successfully employed as amonopropellant.

The compound bis-(fluoroformyl)-peroxide, can be easily formed byintimately reacting 0 CO and F at a temperature between 0C and 50C. Theproduct of the reaction is a clear liquid, C F O,,. The chemicalequation for this reaction can be represented by the equation Thecompound has a boiling point of l5.9C and it crystallizes into a whitemass at 43C. The compound can also be prepared according to theprocedure as set forth by A. .I. Arvia, et al., Quim. Arg., Vol. 50, p.135-143, 1962 and in Chemical Abstracts, Vol. 54, p. 16384 h, 1960.

Bis-(fluoroformyl)-peroxide is chemically and physically suited as a gasgenerator because it readily decomposes at C and above to give CO COFand O in a mo] ratio of 1:1:O.5. The chemical decomposition can berepresented by the equation l O A COF +CO +V2O The products formed bythe decomposition of bis-(fluoroformyD-peroxide, CO COF and 0 are quitecompatible with halogen fluorides such as chlorine trifluoride, brominepentafluoride. chlorine pentafluoride and the like, and with oxygenoxidizers such as dinitrogen tetroxide and the like at elevatedtemperatures. In addition, the decomposition reaction products ofbis-(fluoroformyl)-peroxide are non-explosive, non-catastrophic and canbe contained in non-specific tankage housing. Accordingly, it will bereadily seen to those skilled in the present art thatbis-(fluoroformyl)-peroxide is ideally suited as a monopropellant gasgenerator.

An embodiment of this invention as set forth in FIG. 1, consists of agas generator 10, provided with a suitable heating means 11, such as aninduction heating coil or like device, connected to a power source 13,such as a battery or the like. A conduit 14 is connected between gasgenerator and turbopump 12, to provide power to turbine blade foroperating oxidizer pump 16 and fuel pump 18. Turbopump assembly 12comprises an oxidizer pump 16 and fuel pump 18, with turbine blade 20therebetween. The oxidizer pump 16 is fed from oxidizer tank 22 withsuitable exit means 26 to a combustion chamber (not shown) and fuel pump18 is fed from fuel tank 24 with suitable exit means 28 to theaforementioned combustion chamber.

Turning now to the accompanying drawing, FIG. 1; in operation, said gasgenerator is charged with bis- (fluoroformyl)-peroxide and selectivelyheated to 100C or above to produce the non-reactive and noncorrosivegases as described above, COF CO and 0 The gases formed as a result ofthermal decomposition are next conveyed through the conduit 14 to turnthe turboblade 20 which in turn provides the necessary power to operatepump 16 and 18 for conveying the oxidizer and fuel to the combustionchamber for powering the rocket engine. Thus, it can be seen, that themonopropellant gas generator of this invention can be used in agaspressurized generator system or the like, or in a system similar to aconventional gas pressurized rocket system. The gases produced onheating the monopropellant to its gaseous decomposition point are fed inby manifold or pipe to the turbine or the like and are there expanded inthe turbine nozzle to run the turbine. The monopropellant gas generatorof this invention can be entirely self-starting and it does not requireany special starting provisions or catalytic decomposition agents.

Referring now to accompanying drawing, FIG. 2; in operation, is ageneral pressure fed propellant system wherein the monopropellantbis-(fluoroformyl)- peroxide in tank 34 is pressurized by means of asmall amount of a suitable gas such as nitrogen or the like stored intank 30 through a pressure regulator 32. The monopropellant is conveyedfrom tank 34 through suitable means, such as a conduit, pipe or thelike, into an injector 36 which feeds the monopropellant into a thermalinitiation unit 38 wherein the monopropellant thermally decomposes toproduce COF CO and 0 The newly formed gases are then fed from unit 38into propellant tank 40 which contains chlorine trifluoride or otherlike agents, and forces said agent under pressure through a suitableconduit into thrust chamber 42. While schematic drawing FIG. 2 depicts asingle propellant ullage flow system, it is to be understood that inactual practice a bipropellant system, mixing for example, methylhydrazine and chlorine trifluoride, would be employed. In a bipropellantsystem a single gas generator interconnected to two tanks similar totank 40 could be employed, or two independent gas generator systemshaving their own ullage flow may be used for feeding oxidizers and fuelsinto a thrust chamber.

Obviously, many modifications and variations of the instant inventionare possible in the light of the above teachings, and it is, therefore,to be understood that within the scope of the claims, the invention maybe practiced otherwise as specifically described.

I claim:

l. The process comprising thermally decomposingbis-(fluoroformyl)-peroxide at a temperature above about C to produce agaseous product consisting essentially of oxygen, carbon dioxide andcarbonyl fluoride in a mol ratio of about 0.5: 1 fl and using saidgaseous product as a source of power.

2. The process of claim 1 in which the gaseous product is used as asource of power to drive a turbine.

3. The process of claim 1 in which the gaseous product is used as asource of power for conveying a fuel into a rocket thrust chamber.

4. The process of claim 1 in which the gaseous product is used as asource of power for conveying an oxidizer into a rocket thrust chamber.

2. The process of claim 1 in which the gaseous product is used as asource of power to drive a turbine.
 3. The process of claim 1 in whichthe gaseous product is used as a source of power for conveying a fuelinto a rocket thrust chamber.
 4. The process of claim 1 in which thegaseous product is used as a source of power for conveying an oxidizerinto a rocket thrust chamber.